Traditional high volume manufacture and assembly of products, machines and vehicles has occurred in large assembly plants. These assembly plants have included multiple assembly lines where components are gathered, assembled and connected together. In the manufacture and assembly of vehicular bodies, the bodies typically include a skeleton of sheet metal components that are welded together through resistance spot welding, seam welding and brazing techniques to form what are commonly called “body-in-white” (BIW) structures.
With the growing need to efficiently build vehicles and accommodate varying consumer demand, assembly plants have strived to employ flexible build processes so that different vehicles and varying vehicle models including alternate vehicle bodies, can be built along the same assembly lines. The ability to quickly change over from building one type of body to another causes significant difficulty for facilities due to the limited amount of space around assembly lines and the time required to change over equipment and components that are specific to one vehicle body.
The design, build, installation and commission (testing or prove-out) of new assembly lines is an enormously time consuming and expensive endeavor for both suppliers and the customer vehicle original equipment manufacturers (OEM's) ultimately responsible for operation of the assembly facilities and production of the vehicles. Due to increased competition and consumer demand, there is continuous pressure from the OEM's for lower cost and higher efficiency assembly systems (higher vehicle or unit per hour throughput) and for those assembly systems to be 100 percent operational in a shorter amount of time.
Due to the multiple assembly systems, equipment and components that require sequenced operation to assemble a vehicle (or other product), the design of the overall assembly line traditionally required many stages. For example, the final design of equipment, for example called “Time B” equipment, that relies on a supporting structure, for example called “Time A” equipment, traditionally could not be completed until the design of its Time A supporting structure is complete. Once the various Time A support infrastructure and individual assembly systems were designed, built and installed, a substantial portion of the commission or testing of the Time B equipment traditionally could not occur until all of the Time A support structure and equipment is delivered and installed at the OEM assembly plant. This is further complicated by OEM's typically awarding portions of the assembly line Time A and Time B equipment to many different suppliers to leverage the respective supplier's expertise. If a supplier falls behind in the design, build or installation of Time A equipment, that can delay Time B equipment suppliers causing a cascading of delays through the remainder of the design, build, installation and commission stages. It would be further advantageous to have as many of the assembly equipment and systems be generic or non-model specific. That is, these systems and equipment may be used to build most or all variations of a product or vehicle which may have different models or features. These non-model specific systems and equipment (Time A) could then be fabricated, installed and commissioned even when final decisions about the product to be produced have not been made (which affect the Time B non-generic or model-specific assembly equipment and systems).
It has further been time consuming and costly for vehicle OEM's to change over an assembly plant or assembly lines to a new vehicle model or different vehicle altogether. Even simple to moderate changes to the assembly line equipment infrastructure can take days or weeks to complete leading to costly production downtime.
Prior assembly systems have employed specific assembly plant layouts to decrease the plant floor space required and increase efficiency in operations and vehicle throughput. For example, the ComauFlex system, produced by the same assignee of the present invention, has been widely employed by OEM's the details of which can be reviewed in U.S. Pat. No. 8,201,723 the entire contents of which is incorporated herein by reference and briefly discussed below. Details of variations of the ComauFlex assembly plant layout systems can further be found in U.S. Pat. Nos. 8,869,370; 8,713,780 and U.S. Patent Application Publication 2012/0304446 all assigned to assignee of the present invention and all incorporated herein by reference. These prior systems further reduced the need to store to-be-installed components and subassemblies next to the assembly line and specific assembly stations or cells which cluttered the assembly floor and complicated logistics.
Prior assembly systems have employed some modular vehicle assembly subsystems which provided advantages in new installations and accommodating batch and random vehicle builds where different vehicle models or types of vehicles could be built along the same assembly line with reduced changeover time. Prior assembly subsystems have employed modular robotic assembly stations or cells which could be placed end-to-end to accommodate a specified assembly line or series of operations. For example, each assembly station or cell included a modular, precision-manufactured to close tolerances scaffold frame structure and could be selectively equipped with the necessary number of industrial, multi-axis robots and end effectors for a specified assembly operation. Details can be found in the above-referenced U.S. Pat. Nos. 8,201,723; 8,869,370; 8,713,780 and U.S. Patent Application Publication 2012/0304446 all incorporated herein by reference.
Despite the numerous efficiencies and advantages prior assembly systems provide, many of the above-referenced complexities and disadvantages continue in the design, build, assembly and commission of these equipment and process subsystems, and the assembly system as a whole, in the field. For example, peripheral equipment used in vehicle assembly, for example liquid sealant dispensing devices and fastener feeders, required to support the robot assembly operations at a particular assembly station are traditionally placed on the plant floor and separate conveying systems required to transfer the sealant or fasteners to the robots positioned in the assembly cell for use. As another example, where floor-mounted robots are needed in an assembly cell, much time and effort is traditionally needed to precisely locate and mount the robots in positional relation to the other robots and equipment in the assembly cell. As another example, safety fencing used around an assembly line or cell cannot be designed and tested until most of the assembly cell equipment is designed and installed at the assembly facility.